Parallel resistance welding is used for rectangular or square packages. Projection welding is used for TO-can devices.
Prior to sealing parts they are put through a Vacuum bake-out process to remove moisture and other residues from the component surfaces. Devices can be hermetically sealed in a wide variety of inert gas atmospheres including N2, Ar, O2, depending on the customers exact requirements.
Fine and Gross leak tests are carried out to MIL-STD-883.

Optocap have achieved leak rates of <5E-9 for a fiber coupled butterfly package. This offers the potential of reducing the length of lifetime tests in certain applications.
Optocap’s expertise and capability in Hermetic Sealing will reduce risk and reduce time to market as well as providing a cost-effective manufacturing option.

Flip Chip Assembly

Optocap has detailed know-how in a wide variety of processes and materials;

Flip chip (also known as direct chip attach) is the process whereby a semiconductor die is attached bond pad side down to a substrate or carrier. The electrical connection is made by means of a conductive bump on the die bond pad. Once the die is connected the stand-off distance between the die and substrate is typically filled with a non-conductive adhesive referred to as underfill. The underfill provides stress relief between the die and carrier, provides robustness, and protects the component from any moisture ingress.

Flip chip bonding can offer a number of advantages over other interconnection processes. Flip chip bonding can provide higher I/O count as the whole area of the die can be used for connections. Due to the short interconnections paths, compared to wire bonds, the speed of a device can be improved. In addition as wire bonds loops are removed it provides a smaller form factor.

X-ray and cross-sections can be used to assess the interconnection joints and temperature cycling used to assess the reliability.

Optocap’s expertise and capability in flip chip bonding will reduce risk and reduce time to market for your flip chip bonding requirements as well as providing a cost-effective manufacturing option.

Wire Bonding & Ribbon Bonding

Gold (Au) ball wire bonding

Wire bond diameters from 17um to 33um can be handled with a capability for fine pitch wire bonding down to 50um.

Wire bonding is one of the main method of making interconnections between a semiconductor die and a package or substrate. We use fully automatic machines for the services detailed above.

Optocap works closely with our customers at the package design stage to ensure that design for manufacturing techniques are applied and wire bond design rules, where possible, are adhered to. This co-design activity is crucial in the development a high yield, fully automated and fully optimized wire bond process.

By controlling and optimizing key wire bond process and material parameters such as ultrasonic energies and wire specification a robust and reliable wire bond processes can be developed.

Package Design Services

Optocap utilize Design for Manufacturing (DFM) techniques to ensure that any designs are compatible with a low cost, high yield assembly process.

Thermo-mechanical finite element modelling will be used at the front end of the package design to assess the mechanical design positional stability and the component temperature gradients over package temperature exposures and device thermal loading. This activity will drive the definition and design of the package, layout of components, material selections and thickness for resistance to thermal gradient warpage, heat-sinking and cooling options, and appropriate joining materials to ensure expansion matching of materials.

Optical modeling software will be used to define aspects of the module performance and its sensitivity to the positional placement of the components.

Our optical design capabilities range from the simple selection of a ball lens for coupling the output of an optical fibre into a photodiode, to providing a much wider module design service. This may include proof-of-concept design evaluation, opto-mechanical and thermal tolerancing leading to material selection, and the generation of mechanical piece part drawings through the use of Solidworks. In addition, in collaboration with established optical component providers, we can assess the merits of stock verses custom optics for your design solutions.